EP0459404A2 - Magnetoresistance-effect thin film head - Google Patents
Magnetoresistance-effect thin film head Download PDFInfo
- Publication number
- EP0459404A2 EP0459404A2 EP91108704A EP91108704A EP0459404A2 EP 0459404 A2 EP0459404 A2 EP 0459404A2 EP 91108704 A EP91108704 A EP 91108704A EP 91108704 A EP91108704 A EP 91108704A EP 0459404 A2 EP0459404 A2 EP 0459404A2
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- EP
- European Patent Office
- Prior art keywords
- magnetic field
- thin film
- sensing element
- film head
- field sensing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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- 239000010409 thin film Substances 0.000 title claims abstract description 85
- 239000004020 conductor Substances 0.000 claims abstract description 51
- 239000000758 substrate Substances 0.000 claims abstract description 14
- 239000002184 metal Substances 0.000 claims description 11
- 229910052751 metal Inorganic materials 0.000 claims description 11
- 238000010276 construction Methods 0.000 description 9
- 230000007613 environmental effect Effects 0.000 description 5
- 239000010408 film Substances 0.000 description 5
- 230000007797 corrosion Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 230000005330 Barkhausen effect Effects 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 230000020169 heat generation Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 238000000992 sputter etching Methods 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/33—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only
- G11B5/39—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects
- G11B5/3903—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects using magnetic thin film layers or their effects, the films being part of integrated structures
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/31—Structure or manufacture of heads, e.g. inductive using thin films
- G11B5/3103—Structure or manufacture of integrated heads or heads mechanically assembled and electrically connected to a support or housing
- G11B5/3106—Structure or manufacture of integrated heads or heads mechanically assembled and electrically connected to a support or housing where the integrated or assembled structure comprises means for conditioning against physical detrimental influence, e.g. wear, contamination
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/40—Protective measures on heads, e.g. against excessive temperature
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- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Magnetic Heads (AREA)
Abstract
Description
- The present invention relates to a magnetoresistance-effect thin film head and, more specifically, to a magnetoresistance-effect thin film head capable ensuring high reliability even in operation in a high-temperature, high-humidity environment.
- Fig. 12 shows a previously proposed magnetoresistance-effect thin film head A comprising a substrate 1, a magnetic
field sensing element 2, i.e., a magnetoresistance-effect element (hereinafter referred to as "MR element") formed on the substrate 1 perpendicularly to the sliding surface a of a magnetic recording medium, a conductivelayer having electrodes MR element 2 to supply a sense current to theMR element 2 in the direction of a signal magnetic field created by the magnetic recording medium. The thin film head A employs a bias magnetic field creating conductor (hereinafter referred to simply as "bias conductor") 5 formed on aninsulating layer 4 formed over theMR element 2 so as to extend across theMR element 2 as means for applying a bias magnetic field. An optimum bias magnetic field can be created by varying the current flowing through thebias conductor 5. In Fig. 12, indicated at 6 is an insulating layer, at 7 is a magnetic shielding layer formed over the MR element to enhance the resolution, and ℓ₁ is a gap. The construction of theMR element 2 consisting of twomagnetic films intermediate layer 2a formed between themagnetic films - However, in fabricating the thin film head A of Fig. 12, the
bias conductor 5 and the electrode layer having theelectrodes - On the other hand, since a sense current is supplied in a direction perpendicular to the sliding surface a for the foregoing thin film head provided with the two-
layer MR element 2, theelectrodes MR element 2, and thebias conductor 5 can be formed simultaneously as shown in Fig. 13 (Japanese Patent Laid-open (Kokai) No. 1-116912). This thin film head B can be constructed so that the gap ℓ₂ thereof is smaller than the gap ℓ₁ of the thin film head A of Fig. 12 (ℓ₁ > ℓ₂). However, the size of theMR element 2 of the thin film head B of Fig. 13 must be reduced to increase the recording density, and hence the contact areas and widths of theelectrodes electrodes MR element 2, and thebias conductor 5 are formed simultaneously, heat and noise increase due to increase in the resistance. Furthermore, since the width of a portion of thebias conductor 5 extending over and across theMR element 2 is small, thebias conductor 5 is unable to apply a bias magnetic field uniformly to theMR element 2. - The
electrodes MR element 2 having one side exposed in the sliding surface a, and thefront electrode 3A having one side exposed in the sliding surface a are formed, in most cases, of a metal having a comparatively low resistance, such as Au, Cu or Al, to suppress heat generation and noise generation. However, Au is expensive and is liable to come off theMR element 2 during machining for forming the sliding surface a because Au is soft and inferior in adhesive property, Cu is readily oxidized, inferior in moisture resistance and corrosion resistance, and unreliable in use in a high-temperature, high-humidity environment, and the same may be said of Al. - In view of the foregoing problems, it is an object of the present invention to provide a magnetoresistance-effect thin film head having a gap of a reduced size and capable of dealing with high-density recording.
- Another object of the present invention is to provide a magnetoresistance-effect thin film head capable of performing its intended function in a high reliability even under high-temperature, high-humidity environmental conditions.
- In one aspect of the present invention, a magnetoresistance-effect thin film head comprises a substrate (12) a magnetic field sensing element (13) formed on the substrate (12), an electrode layer (15) having electrodes extending respectively from the opposite ends of the magnetic field sensing element (13) to supply a sense current to the magnetic field sensing element (13) in the direction of a signal magnetic field, an insulating layer (14) formed over the magnetic field sensing element (13), a bias magnetic field creating conductor (16) formed on the insulating layer (14) so as to extend across the magnetic field sensing element (13), and a magnetic shielding layer (19) shielding the magnetic field sensing element (13), and is characterized in that a conductive pattern (17) includes at least a portion of the electrode layer (15) and a portion of the bias magnetic field creating conductor (16).
- In another aspect of the present invention, a magnetoresistance-effect thin film head comprises a substrate (12) a magnetic field sensing element (13) formed on the substrate (12), an electrode layer (15) having electrodes extending respectively from the opposite ends of the magnetic field sensing element (13) in the direction of a signal magnetic field, an insulating layer (14) formed over the magnetic field sensing element (13), a bias magnetic field creating conductor (16) formed on the insulating layer (14) so as to extend across the magnetic field sensing element (13), and a magnetic shielding layer (19) shielding the magnetic field sensing element (13), and is characterized in that the electrode layer (15) consists of a principal metal conductor (27) and a moisture-resistant conductor (26), and a portion of the electrode layer (15) contiguous with the sliding surface is formed of the moisture-resistant conductor (16).
- The magnetoresistance-effect thin film head in the first aspect of the present invention has a simple layered structure because a portion of the electrode layer (15) of the magnetic field sensing element (13) and a portion of the bias magnetic field creating conductor (16) are included in the conductive pattern (17), and hence the gap can be formed in a reduced size. Since the conductive pattern (17) has a portion of the bias magnetic field creating conductor (16), the bias magnetic field creating conductor (16) covers the end portion of the magnetic field sensing element (13) and, consequently, a bias magnetic field can uniformly be applied to the magnetic field sensing element (13). Since the area of contact between the magnetic field sensing element (13) and the electrode layer (15) is sufficiently large and the electrode layer (15) has a sufficiently large width even if the magnetic field sensing element (13) is formed in a reduced size, heat generation and noise generation are suppressed, and hence the thin film head is able to deal with high-density recording. Forming the conductive pattern (17) so as to include a portion of the electrode layer (15) and a portion of the bias magnetic field creating conductor (16) reduces the number of terminals of the thin film head.
- Since the magnetoresistance-effect thin film head in the second aspect of the present invention is provided with the electrode layer (15) of the magnetic field sensing element (13) having a portion contiguous with the sliding surface formed of the moisture-resistant conductor (26), the electrode layer (15) is protected from oxidation and corrosion, so that the magnetoresistance-effect thin film head performs its function at a high reliability even under high-temperature, high-humidity environmental conditions.
- The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in connection with the accompanying drawings, in which:
- Figures 1 and 2 are a plan view and a sectional view taken on line A-a in Fig. 1, respectively, of a magnetoresistance-effect thin film head in a first embodiment according to the present invention;
- Figure 3 is a circuit diagram of an equivalent circuit whose behavior is identical with that of the magnetoresistance-effect thin film head of Fig. 1;
- Figures 4 and 5 are a plan view and a sectional view taken on line B-B in Fig. 4, respectively, of a magnetoresistance-effect thin film head in a second embodiment according to the present invention;
- Figure 6 is a plan view of a magnetoresistance-effect thin film head in a third embodiment according to the present invention;
- Figure 7 is a circuit diagram of an equivalent circuit whose behavior is identical with that of the magnetoresistance-effect thin film head of Fig. 6;
- Figures 8 and 9 are a plan view and a sectional view taken on line C-c in Fig. 8, respectively, of a magnetoresistance-effect thin film head in a fourth embodiment according to the present invention;
- Figures 10 and 11 are graphs showing results of environmental tests of the thin film head in accordance with the present invention and a conventional thin film head, respectively; and
- Figures 12 and 13 are sectional views of conventional magnetoresistance-effect thin film heads.
- Magnetoresistance-effect thin film heads embodying the present invention will be described hereinafter with reference to the accompanying drawings.
- In a magnetoresistance-effect thin film head in a first preferred embodiment according to the present invention, at least a portion of a conductor of a electrode layer 15 connected either to the front end or rear end of a MR element, and a portion of a bias conductor (16) are included in a
conductive pattern 17, and a terminal connected to theconductive pattern 17 is grounded. Referring to Figs. 1 and 2, a thin film head 11 of such a construction having a sliding surface a which faces a magnetic recording medium, such as a magnetic disk, is fabricated by forming aMR element 13 on asubstrate 12 so as to extend in a direction perpendicular to the sliding surface a, coating theMR element 13 with aninsulating layer 14, formingcontact holes insulating layer 14 at positions corresponding respectively to the front and rear ends of theMR element 2, and simultaneously forming arear electrode 15B connected through thecontact hole 14b to the rear end of theMR element 13, abias conductor 16, and aconductive pattern 17 having a portion forming a front electrode, not shown, connected through thecontact hole 14a to theMR element 13 and a portion forming a portion of thebias conductor 16 in a single process. A portion of thebias conductor 16 included in theconductive pattern 17 extends over and across theMR element 13. To enhance the resolution of the thin film head, theMR element 13 is shielded by amagnetic shielding layer 19 formed on aninsulating layer 18. TheMR element 13 consists of twomagnetic films intermediate layer 13a formed between the twomagnetic films MR element 13 suppresses the generation of Barkhausen noise, i.e., noise attributable to domain wall replacement. The front end of theMR element 13, and a portion of theconductive pattern 17 corresponding to the front end of theMR element 13 are exposed in the sliding surface a. A terminal t₁ connected to theconductive pattern 17 is connected to a ground potential Vss, a terminal t₂ connected to therear electrode 15B connected to the rear end of theMR element 13 is connected to an amplifier, not shown, to apply a predetermined voltage to the terminal t₂ by a constant-voltage power supply. A predetermined voltage is applied to a terminal t₃ connected to thebias conductor 16. - A sense current iS supplied through a contact portion 17a of the
conductive pattern 17 and therear electrode 15B to theMR element 13 of the thin film head 11 in the direction of a signal magnetic field created by the magnetic disk, and a bias current iB is supplied through thebias conductor 16 and theconductive pattern 17 to theMR element 13 in a direction substantially perpendicular to the direction of flow of the sense current iS. Fig. 3 shows an equivalent circuit whose behavior is identical with that of the thin film head 11. Referring to Fig. 3, R₁ represents the resistance of theMR element 13 and therear electrode 15B, R₂ represents the resistance of thebias conductor 16, i.e., a portion of thebias conductor 16 before theconductive pattern 17, R₃ represents the resistance of theconductive pattern 17. An output variation ΔV in the output of theMR element 13 resulting from a resistance variation ΔR in the resistance of theMR element 13 caused by the variation of magnetic flux applied to theMR element 13 is expressed by:
The output variation ΔV corresponds to the variation of the potential difference between the terminal t₁ connected to theconductive pattern 17 and the terminal t₂ connected to therear electrode 15B of theMR element 13 when the current is maintained constant. - It is obvious from Expression (1) that the output variation of the thin film head 11 is the same as that of the conventional thin film head. Accordingly, voltages to be applied respectively to the terminal t₂ of the
rear electrode 15B connected to the rear end of theMR element 13 and the terminal t₃ of thebias conductor 16 can individually be determined, the bias current iB flows through theconductive pattern 17 across theMR element 13 if iS ≠ -iB to apply an appropriate bias magnetic field to theMR element 13. If either the voltage V₁ applied to the terminal t₂ of therear electrode 15B of theMR element 13 or the voltage V₂ applied to the terminal t₃ of thebias conductor 14 is a negative voltage, the current |iS - iB| that flows through theconductive pattern 17 having the resistance R₃ can be reduced to suppress the generation of heat and noise. - In fabricating the thin film head 11, the electrodes of the
MR element 13, and the bias conductor are formed simultaneously by a single process, the thin film head 11 can be formed in a simple layered construction and has a small gap ℓ₃. Since the front electrode of theMR element 13 and a portion of the bias conductor are included in theconductive pattern 17, a portion 17a of theconductive pattern 17 in contact with the front end of theMR element 13, and acontact portion 17b of theconductive pattern 17 in contact with the the rear end of theMR element 13, i.e., a portion of therear electrode 15B in contact with theMR element 13, can be formed in a sufficiently large contact area even if theMR element 13 is formed in a comparatively small size to deal with high-density recording. Since a portion of theconductive pattern 17 serving as the bias conductor covers theMR element 13 including the front end of theMR element 13, a bias magnetic field can be applied uniformly to theMR element 13. Basically, the construction of the thin film head thus fabricated, prevents layer short between the electrode layer for theMR element 13, and the bias conductor, which enhances the reliability of the thin film head. Furthermore, the thin film head in accordance with the present invention has three terminal where as the conventional thin film head has four terminals. -
- Figs. 4 and 5 show a
thin film head 21 in second embodiment according to the present invention. Thethin film head 21, similarly to the thin film head 11 in the first embodiment shown in Figs. 1 and 2, has a front electrode connected to the front end of aMR element 13 and included in aconductive pattern 17 and is identical in construction with the thin film head 11 shown in Figs. 1 and 2, except that aslit 22 is formed in theconductive pattern 17 of thethin film head 21 to separate aportion 15A of theconductive pattern 17 serving as the front electrode of theMR element 13, and a portion 16a of theconductive pattern 17 serving as a bias conductor from each other and to join theportion 15A to abias conductor 16 at a junction p at a position outside an area corresponding to theMR element 13 so that a sense current iS and a bias current iB join at a position outside the area corresponding to theMR element 13. - In the
thin film head 21, the bias current iB is not disturbed while the same flows over theMR element 13, so that a bias magnetic field can further satisfactorily be applied to theMR element 13. Since theconductive portions 15A and thebias conductor 16 joins at a position very close to theMR element 13, increase in the resistance of theconductive portion 15A connected to the front end of theMR element 13 is insignificant. Thethin film head 21 has the same advantages as those of the thin film head 11 shown in Fig. 1. - Fig. 6 shows a
thin film head 23 in a third embodiment according to the present invention. Thethin film head 23 is identical in construction with the thin film head 11 shown in Fig. 1, except that, in thethin film head 23, a portion of arear electrode 15B connected to the rear end of aMR element 13 and a portion of abias conductor 16 are included in aconductive pattern 24, and a terminal t₄ is connected to theconductive pattern 24 as a common terminal for therear electrode 15B and thebias conductor 16. Fig. 7 shows an equivalent circuit whose behavior is identical with that of thethin film head 23. In Fig. 7, resistances R₁, R₂ and R₃ corresponds respectively to those in Fig. 3, and R₄ represents the resistance of a portion of theconductive pattern 24 serving as the rear electrode. Although thethin film head 23 does not allow the individual selection of a bias current iB to be supplied to thebias conductor 16 and a sense current iS to be supplied to theMR element 13, thethin film head 23 has only two terminals t₁ and t₄. Other advantages of thethin film head 23 are the same as those of the thin film head 11 shown in Fig. 1. - Figs. 8 and 9 shows a thin film head 25 in a fourth embodiment according to the present invention. The thin film head 25 is capable of functioning at a high reliability under high-temperature, high-humidity environmental conditions. Basically, the thin film head 25 has an electrode layer 15 for a
MR element 13, consisting of a metal layer having a comparatively small resistivity and a moisture-resistant conductive layer, and a portion of the electrode layer contiguous with the sliding surface a of the thin film head 25 is formed only of a portion of the moisture-resistant conductive layer. - Referring to Figs. 8 and 9, the
MR element 13 of the said two-layer construction is formed on a substrate so as to extend in a direction perpendicular to the sliding surface. An electrode layer 15 for supplying a sense current iS to the MR element in the direction of a signal magnetic field has afront electrode 15A connected to the front end of theMR element 13 and arear electrode 15B connected to the rear end of theMR element 13. Abias conductor 16 is formed so as to extend across theMR element 13 on an insulatinglayer 14 covering theMR element 13. Amagnetic shielding layer 19 is formed on an insulatinglayer 18 so as to shield theMR element 13. Thefront electrode 15A and therear electrode 15B connected to theMR element 13 consist of a moisture-resistantconductive layer 26 formed of a moisture-resistant material, such as Ti, Mo, W, Cr, SuS or C, and a principal conductive layer 27 formed of a metal having a comparatively small resistivity, such as Cu, Au or Al. If the principal conductive layer 27 is formed of a metal having an inferior adhesive property, such as Au, abonding metal layer 28, such as a Ti layer or a Mo layer, is formed on the principal conductive layer 27. A portion of thefront electrode 15A contiguous with the sliding surface a, namely, a portion extending as deep as 0.5 µm or above from the sliding surface a, is formed only of the moisture-resistantconductive layer 26. In this embodiment, a portion of thefront electrode 15A connected to theMR element 13 is formed only of the moisture-resistantconductive layer 26. Thebias conductor 16 may be the same laminated metal layer as that forming theelectrodes front electrode 15A can readily be formed by a process comprising steps of sequentially forming the moisture-resistantconductive layer 26, the principal conductive layer 27 and thebonding metal layer 28 in that order in the shape of the electrode on the insulatinglayer 14 including a contact hole, etching a portion of the superposedbonding metal layer 28 contiguous with the sliding surface a and connected to theMR element 13, and a portion of the principal conductive layer 27 corresponding to that of thebonding metal layer 28 by ion milling using a resist mask, and stopping the etching operation upon the exposure of the moisture-resistant layer 26. - Thus, the
front electrode 15A excluding a portion thereof contiguous with the sliding surface a is formed of the principal conductive layer 27 and the moisture-resistant layer, and only the moisture-resistant layer 26 of thefront electrode 15A is exposed in the sliding surface a, thefront electrode 15A exposed in the sliding surface a is not deteriorated by oxidation and corrosion even if the thin film head 25 is used under high-temperature, high-humidity conditions, so that the thin film head 25 maintains its high reliability. - Figs. 10 and 11 are graphs showing results of environmental tests respectively of the thin film head in the fourth embodiment according to the present invention provided with a Ti film as the moisture-
resistant layer 26, and a conventional thin film head under high-temperature, high-humidity (temperature: 60°C, humidity: 90%) conditions. As is obvious from Fig. 11, the resistance of the MR element of the conventional thin film head between the electrodes increases sharply with time, which proves that the electrodes are deteriorated by corrosion. On the other hand, as indicated by a curve I in Fig. 10, the resistance of the MR element of the thin film head of the present invention between the electrodes remains substantially constant for a long time, which proves that the electrodes are not deteriorated. In Fig. 10, a straight line II indicates a fraction nondefective. As is obvious from Fig. 10, the thin film head of the present invention is capable of enduring long service under high-temperature, high-humidity conditions. - Naturally, the techniques applied to the thin film head 25 can be applied also to the thin film heads 11, 12 and 23.
- Although the invention has been described as applied to a so-called single-shielded thin film head, naturally, the present invention is applicable also to a double-shielded thin film head provided with a MR element having upper and lower sides shielded magnetic shielding layers, respectively.
- The gap of the magnetoresistance-effect thin film head in the first aspect of the present invention can readily be formed in a reduced size even if the MR element is formed in a reduced size to cope with high-density recording by forming a conductive layer so as to include a portion of the electrode connected to the MR element, and a portion of the bias magnetic field creating conductor. Such a construction of the magnetoresistance-effect thin film head enables the uniform application of a bias magnetic field to the MR element, reduces the number of external terminals, prevents layer short between the electrodes of the MR element and the bias magnetic field creating layer, and enhances the reliability of the magnetoresistance-effect thin film head.
- The electrode having a portion contiguous with the sliding surface and formed of a moisture-resistant material employed as the front electrode of the MR element of the magnetoresistance-effect thin film head in the second aspect of the present invention is free from deterioration even if the magnetoresistance-effect thin film head is used under high-temperature, high-humidity conditions, which ensures the high reliability of the magnetoresistance-effect thin film head.
- Although the invention has been described in its preferred form with a certain degree of particularity, obviously many changes and variations are possible therein. It is therefore to be understood that the present invention may be practiced otherwise than as specifically described herein without departing from the scope and spirit thereof.
Claims (2)
- A magnetoresistance-effect thin film head (11) comprising: a substrate (12); a magnetic field sensing element (13) provided on the substrate (12); an electrode layer (15) having portions respectively extending from the opposite ends of the magnetic field sensing element (13) to supply a sense current to the magnetic field sensing element (13) so that the sense current will flow in the direction of a signal magnetic field; an insulating layer (14) formed over the magnetic field sensing element (13); a bias magnetic field creating conductor (16) formed on the insulating layer (14) so as to extend across the magnetic field sensing element (13); and a magnetic shielding layer (19) shielding the magnetic field sensing element (13);
characterized in that at least a portion of the electrode layer (15) and a portion of the bias magnetic field creating conductor (16) are included in a conductive pattern (17). - A magnetoresistance-effect thin film (21) head comprising: a substrate (12); a magnetic field sensing element (13) provided on the substrate (12); an electrode layer having (15) portions respectively extending from the opposite ends of the magnetic field sensing element (13) to supply a sensing current to the magnetic field sensing element (13) so that the sense current will flow in the direction of a signal magnetic field; an insulating layer (14) formed over the magnetic field sensing element (13); a bias magnetic field creating conductor (16) formed on the insulating layer (14) so as to extend across the magnetic field sensing element (13); and a magnetic shielding layer (19) formed over the magnetic field sensing element (13);
characterized in that the electrode layer (15) consists of a principal conductive metal conductor (27) and a moisture-resistant conductor (26), and
a portion of the electrode layer (15) contiguous with the sliding surface is formed of the moisture-resistant conductor (26).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP140685/90 | 1990-05-30 | ||
JP2140685A JPH0434713A (en) | 1990-05-30 | 1990-05-30 | Magneto-resistance effect type thin film head |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0459404A2 true EP0459404A2 (en) | 1991-12-04 |
EP0459404A3 EP0459404A3 (en) | 1992-01-15 |
EP0459404B1 EP0459404B1 (en) | 1996-01-24 |
Family
ID=15274376
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP91108704A Expired - Lifetime EP0459404B1 (en) | 1990-05-30 | 1991-05-28 | Magnetoresistance-effect thin film head |
Country Status (4)
Country | Link |
---|---|
US (1) | US5351158A (en) |
EP (1) | EP0459404B1 (en) |
JP (1) | JPH0434713A (en) |
DE (1) | DE69116602T2 (en) |
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JP3389892B2 (en) * | 1999-09-24 | 2003-03-24 | 株式会社村田製作所 | head |
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US7719802B2 (en) * | 2003-09-23 | 2010-05-18 | Seagate Technology Llc | Magnetic sensor with electrically defined active area dimensions |
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JPH01116915A (en) * | 1987-10-29 | 1989-05-09 | Sony Corp | Magneto-resistance type magnetic head |
JPH01116913A (en) * | 1987-10-29 | 1989-05-09 | Sony Corp | Magneto-resistance type magnetic head |
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- 1991-05-28 US US07/706,257 patent/US5351158A/en not_active Expired - Fee Related
- 1991-05-28 EP EP91108704A patent/EP0459404B1/en not_active Expired - Lifetime
- 1991-05-28 DE DE69116602T patent/DE69116602T2/en not_active Expired - Fee Related
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DE3832449A1 (en) * | 1987-09-24 | 1989-04-13 | Hitachi Ltd | MAGNETIC HEAD |
JPH01116915A (en) * | 1987-10-29 | 1989-05-09 | Sony Corp | Magneto-resistance type magnetic head |
JPH01116913A (en) * | 1987-10-29 | 1989-05-09 | Sony Corp | Magneto-resistance type magnetic head |
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Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5351158A (en) * | 1990-05-30 | 1994-09-27 | Sony Corporation | Magnetoresistance effect thin film head with interconnected electrode structure |
EP0613120A2 (en) * | 1993-02-26 | 1994-08-31 | Sony Corporation | Magnetoresistance thin film magnetic head and bias characteristics measuring method |
EP0613120A3 (en) * | 1993-02-26 | 1996-03-20 | Sony Corp | Magnetoresistance thin film magnetic head and bias characteristics measuring method. |
US5875078A (en) * | 1993-02-26 | 1999-02-23 | Sony Corporation | Magnetoresistance thin film magnetic head having reduced terminal count; and bias characteristics measuring method |
EP0651375A1 (en) * | 1993-10-29 | 1995-05-03 | International Business Machines Corporation | Magnetoresistive head |
EP0725388A2 (en) * | 1995-01-31 | 1996-08-07 | Sony Corporation | Magneto-resistance effect type magnetic head operable at optimum biasing point |
EP0725388A3 (en) * | 1995-01-31 | 1996-12-27 | Sony Corp | Magneto-resistance effect type magnetic head operable at optimum biasing point |
US5867350A (en) * | 1995-03-29 | 1999-02-02 | Sony Corporation | Magneto-resistance effect head with insulated bias conductor embedded in shield groove |
EP0770991A3 (en) * | 1995-10-26 | 1998-05-20 | Read-Rite Corporation | Thin film magnetoresistive head with contiguous junction |
US6163437A (en) * | 1997-03-24 | 2000-12-19 | Tdk Corporation | Magnetic head with spin valve effect magnetoresistive element and its manufacturing method |
Also Published As
Publication number | Publication date |
---|---|
JPH0434713A (en) | 1992-02-05 |
EP0459404B1 (en) | 1996-01-24 |
US5351158A (en) | 1994-09-27 |
DE69116602D1 (en) | 1996-03-07 |
DE69116602T2 (en) | 1996-09-05 |
EP0459404A3 (en) | 1992-01-15 |
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